Method of providing support for conductors of an electric filament or discharge lamp

ABSTRACT

An electric lamp comprising a support having continuous supporting members and/or current conductors which are secured in a pinch seal. In order to increase the insensitivity to vibrations, the support which extends at right angles to the axis of the lamp is secured to the side wall of the lamp vessel preferably by a sealing operation.

United States Patent Van Den Berge METHOD OF PROVIDING SUPPORT FOR w CONDUCTORS OF AN ELECTRIC FILAMENT OR DISCHARGE LAMP Hendrik Jan Van Den Berge, Emmasingel, Eindhoven, Netherlands U.S. Philips Corporation, New York, N.Y.

Filed: June 8, 1972 Appl. No.: 261,068

Related U.S. Application Data 128,339, March 26, 1971,

Inventor:

Assignee:

Division of Ser. No. abandoned.

Foreign Application Priority Data Apr. 7, 1970 Netherlands 7004939 U.S. Cl. 316/20, 313/271 Int. Cl. H0lj 9/38 Field of Search 313/318, 252, 253, 254, 313/256, 260, 271, 272, 273, 274, 275, 277, 243; 316/17, 18, 19, 20

Primary ExaminerRoy Lake Assistant Examiner-.l. W. Davie Attorney, Agent, or Firm-Frank R. Trifari [5 7] ABSTRACT An electric lamp comprising a support having continuous supporting members and/or current conductors which are secured in a pinch seal. In order to increase the insensitivity to vibrations, the support which extends at right angles to the axis of the lamp is secured to the side wall of the lamp vessel preferably by a sealing operation.

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INVENTOR. HENDRIK J. VAN DEN BERGE AGENT DAIENTEBMR 2:974 3.801; 178

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- INVENTOR. HENDRIK J. VAN DEN BERGE METHOD OF PROVIDING SUPPORT FOR CONDUCTORS OF AN ELECTRIC FILAMENT OR DISCHARGE LAMP This is a division, of application Ser. No. 128,339, filed Mar. 26, 1971 now abandoned.

The invention relates to an electric filament lamp or gas discharge tube comprising a tubular lamp vessel which is sealed on at least one end by a pinch seal, in which one or more filaments or electrodes and, possibly, a reflecting screen are secured to current conducting members and/or supporting members secured in the pinch seal, said members being secured, in a place inside the lamp vessel, to a common support which extends in a direction transverse to the longitudinal direction of the lamp. Such a lamp is known.

In the known lamp the common support serves as an insulating member in which the current conductors and the supporting members formed as rather stiff wires are held in their correct places within the lamp vessel. It is conventional to keep said support, which is supported by the said rather stiff wires, at a certain distance from the pinch seal in which the wires are secured. The whole assembly built up on said support has a certain freedom of movement inside the lamp vessel so that the sensitivity of this type of lamps to vibrations is rather considerable.

It is the object of the invention to reduce the sensitivity to vibrations of this type of lamps.

For that purpose, the electric lamp according to the invention is characterized in that the support is connected to the side wall of the lamp vessel in one or more places near or at its circumference and assumes a prescribed position relative to said wall.

By securing the support, besides with its supporting wires in the pinch seal, also to the side wall of the lamp vessel, a more stable assembly is obtained as a result of the fact that the support itself can no longer move relative to the lamp vessel. The sensitivity of such lamps to vibrations is then smaller than in the known lamps in which the support in question is supported only by a few wires emerging from the pinch seal. By securing the support to the side wall of the lamp vessel, the mass in the lamp space exposed to vibrations relative to the lamp vessel becomes considerably smaller.

The support can be fixed in various manners at its circumference relative to the side wall of the lamp vessel. To be considered is an enclosure between cams in the side wall of the lamp vessel, so that the freedom of movement of the said assembly is restricted both in the longitudinal and in the radial direction of the lamp vessel. According to a preferred embodiment of the method according to the invention, which is particularly suitable for use in a lamp constructed as a projection filament lamp, the support, however, is sealed to the side wall of the lamp vessel. Once an optical system formed by the combination of filament members and a reflector is secured to the support in a desirable and immovable manner, it assumes an unambiguously prescribed position already prior to the lamp being provided with a pinch seal.

A further embodiment of the lamp according to the invention is characterized in that the side wall of the lamp, viewed along its circumference, comprises a few re-entrant parts to which the support is sealed.

In a further embodiment, the support is an elongate member in which continuous conductors or supporting members are secured, said elongate member being secured at its two ends to the side wall of the lamp vessel according to a fixed position.

The invention provides another important aspect. By fixing, in the lamp according to the invention, the position of the support in question relative to the side wall of the lamp vessel, the possibility is presented of manufacturing this lamp in a manner differing from the conventional manner.

In the manufacture of a known halogen lamp the starting material is a component formed by a beam of quartz glass in which a number of continuous conductors and supports are secured to which the filaments or electrodes are secured. This component is placed in an open tube of quartz glass which comprises an exhaust tube at one end. The widest end of the tube is softened by heating after which said end is deformed to form a pinch seal. Between the beam and the pinch seal there is a part of the lamp space in which the said conductors or supporting members are present. The lamp is then evacuated, filled with a suitable halogen-containing gas and sealed. It is found that in this known method the pinching operation has an adverse influence on the position of the filaments, electrodes or screens arranged carefully in the lamp initially. Actually, this position can easily be changed by performing the pinching operation. Such a changed position can substantially not be corrected afterwards. Consequently the resulting lamp has a poorer optical quality.

It will be obvious that the said influence is substantially negligible if, prior to the pinching operation, the said support is secured to the side wall of the lamp vessel in the above-described manner. Once a filament or electrode has been positioned in the desirable manner, its position will not change during the subsequent pinching operation. The resulting method according to the invention which leads to the manufacture of this type of lamps and which can be readily mechanized is characterized in that the support, viewed over the cross-section of the glass tube, is secured to the side wall of the said tube in a few places prior to forming the pinch seal.

The support is preferably secured to the side wall by first softening the tube in which the support is arranged in a few places of its circumference and then providing in said places a pressure differential on either side of the tube wall. As a result of this operation, the support is immovably sealed to the wall of the tube in said places.

In order that the invention may be readily carried into effect, a few examples thereof will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which FIGS. 1, 2 and 3 are two longitudinal sectional views and a cross-sectional view of a halogen filament lamp for a vehicle headlight comprising a support sealed to the side wall of the lamp vessel; FIG. 3 is a crosssectional view taken on the line IIIIII of FIG. 1, FIG. 1 is a cross-sectional view taken on the line 1-1 of FIG. 3, and FIG. 2 is a cross-sectional view taken on the line IIII of FIG. 1;

FIG. 4 shows another embodiment of a lamp comprising several supports, and

FIGS. 5, 6 and 7 relate to a few stages during the manufacture of this type of lamps.

The halogen twin lamp shown in FIGS. 1, 2 and 3 comprises a lamp vessel 1 of quartz glass which is prosecured together and in which a number of current conductors 13, 15 and 17 are sealed. These conductors are secured in normal manner to sealing foils 19, 21 and 23 which themselves are connected to external conductors 25, 27 and 29. The support '7 comprises on its upper side a number of conductor parts between which the filament members 31 and 33 are secured in the manner shown. 35 is a reflecting screen which is welded to the conductor 17 which serves as a support. With the exception of the filaments which are manufactured from tungsten, the remaining structural components are manufactured from molybdenum with a view of the regenerative cycle inside the lamp which is filled with a suitable halogen-containing gas.

According to the invention, the support 7 which in this embodiment is formed as a beam (9, 11) of quartz glass, is connected at either end to the side wall of the lamp vessel 1. The connection method chosen in this example is a seal between the support 7 and the side wall of the lamp vessel 1.

According to another embodiment shown in FIG. 4, a filament formed from segments 37, 38, 40, 42, 44 and 46 is stretched in known manner between beam-like supports 39 and 41. The supporting members 43, 45 and 47, 49 and 51 have hook-like parts at either end which engage both about the supports 39 and 41 and the intermediate members present between the segments of the filament. Supporting poles 57 and 59 are secured in the supports 39 and 41 as continuous conductors. The poles 57 and 59 are coupled to external conductors 65 and 67 by means of welded sealing foils 61 and 63; the foils are surrounded by a pinch seal 69. In this lamp also, which is constructed as a halogen filament lamp for projecting purposes, the supports 39 and 41 which, viewed in the longitudinal direction of the tubular lamp vessel 71, extend on either side of the composite filament, are each secured at their two ends to the side wall of said lamp vessel. Although a connection between the support and the side wall of the lamp vessel can be produced in various manners, it is to be preferred to construct this connection again in the form of a seal between the support 39 and the side wall of the lamp vessel 71 which are both manufactured from quartz glass.

FIGS. 5, 6 and 7 show how the filament lamps described can be manufactured. FIG. shows a part of a holder construction which comprises a member in the form of tongs having jaws 75 and 77 between which an assembly, constituted by conductors 25, 27, 29, foils 19, 21 and 23, conductors 13, l5, 17, support 7 consisting of parts 9 and 11, filament members 31, 33 and screen 35, is clamped in the manner shown. Across said jaws, a tubular glass member 79 is placed which bears on the abutment 83 and which is shown in broken lines in FIG. 5. This tubular member is held by the jaws 86 and 88 of a member in the form of tongs not shown in detail. This tubular member 79 comprises a narrowed portion 81 in the form of an exhaust tube and engages with its wider lower end on the abutment 83. At a prescribed height relative to the abutment 83, the side wall of the tubular member 79 is softened by means of a few pointed flames 85 and 87 of a very high temperature after the space inside the tubular member has been connected to a line 89 in which a negative pressure prevails. As a result of this the tube wall 79 will be deformed at the heated places in such manner that a reentrant partis formed at the said places and the tube wall is sealed to the support 7. In FIG. 7, the re-entrant parts are denoted by 101 and 103. The jaws and 77 are then opened and removed from the tubular member. A pinch seal is then to be formed as the widest open end of the tubular member 79. For that purpose, the assembly, consisting of tubular member 79 with the foils 19, 21, 23 and conductors 25, 27, 29 freely suspending from said support 7, is held between the jaws 86 and 88 (FIG. 7) and is subjected to a further thermal treatment. For that purpose, the open tube end is softened by heating by means of burner flames directed in the direction of the arrows 109 and 111. By means of squeezing members suitable for the purpose and not shown in detail, the end of said tubular member 79 is deformed to a pinch so that the assembly takes the shape as is shown in FIG. 1. The lamp vessel is then evacuated through the exhaust tube 81, filled with a suitable halogen-containing gas, and the exhaust tube 81 is sealed by a sealing operation, the sealed exhaust tube obtaining the shape as is shown in FIG. 1 (5).

In the above embodiments a beam-shaped support 7 was always used. It will be obvious that other forms of supports may also be considered when using the invention. For example, the support 7 may be in the form of a disc which is secured to the side wall at least in three places of its circumference.

The above-described embodiments included a lamp construction in which filaments and a screen are present.'lt will be obvious that the invention can also be used for a gas discharge lamp in which it is desirable that electrodes supported by a support must assume an accurately prescribed position in a lamp vessel which is sealed at least at one end by a pinching operation.

What is claimed is:

1. A method of manufacturing an electric lamp of the type having a tubular vessel sealed on at least one end by a pinch seal comprising the steps of arranging an assembly constituting elongated lamp members being passed through a support in a predetermined position within an open tube of glass, said members having at least one light emitting element secured thereto and assuming an aligned position relative to the support, said support being formed as a beam; securing the support to the side wall of said tube at either end of the beam in at least two places; subsequent to securing the support, softening the tube by heating at one end to form a pinch seal at a predetermined position relative to said support; evacuating the resultant lamp vessel after said pinch seal is formed; providing said evacuated vessel with an appropriate gas; and sealing the other end of said tube.

2. The method of manufacturing an electric lamp as in claim 1 wherein the support is sealed in at least two places of the circumference of the tube by first softening the tube in which the support is arranged in at least two places of its circumference and then providing at said places a pressure differential on either side of the tube wall.

3. The method as in claim 1 wherein said elongated lamp members include current conducting members and said light emitting element is a filament.

4. The method as in claim 1 wherein said elongated lamp members are supports and said light emitting elements are electrodes. 

1. A method of manufacturing an electric lamp of the type having a tubular vessel sealed on at least one end by a pinch seal comprising the steps of arranging an assembly constituting elongated lamp members being passed through a support in a predetermined position within an open tube of glass, said members having at least one light emitting element secured thereto and assuming an aligned position relative to the support, said support being formed as a beam; securing the support to the side wall of said tube at either end of the beam in at least two places; subsequent to securing the support, softening the tube by heating at one end to form a pinch seal at a predetermined position relative to said support; evacuating the resultant lamp vessel after said pinch seal is formed; providing said evacuated vessel with an appropriate gas; and sealing the other end of said tube.
 2. The method of manufacturing an electric lamp as in claim 1 wherein the support is sealed in at least two places of the circumference of the tube by first softening the tube in which the support is arranged in at least two places of its circumference and then providing at said places a pressure differential on either side of the tube wall.
 3. The method as in claim 1 wherein said elongated lamp members include current conducting members and said light emitting element is a filament.
 4. The method as in claim 1 wherein said elongated lamp members are supports and said light emitting elements are electrodes. 